Diallyl polysulfides (polysulfanes: DASn, where n≧2) and derivatives thereof are found naturally, e.g., in garlic oil (distilled oil of garlic), and have found use in a number of areas of technology, for example as pesticides. It is known that the biological activity of the diallyl polysulfides varies with sulfur chain length, with longer chain length molecules often showing increased activity (1). Within the family of diallyl polysulfides occurring naturally, molecules with more than eight sulfur atoms are unknown. It is expected, however, that these would find enormous potential, and show enhanced or alternative properties to those of known diallyl polysulfides.
As a mark of the potential applications of diallyl polysulfides, some examples of application areas are outlined below, with reference to other published literature and patent applications:
DAS2 and DAS3 (diallyl disulfide and diallyl trisulfide) may be used as nematicides to control pine wood nematodes without side effects to the environment such as the reduction of populations of beneficial organisms, development of tolerance through enhanced degradation and resistance, and through toxicological disturbance to ecosystems that encourage outbreaks of latent insect infestations and induction of toxicity to human and domestic animals (2); DAS2-DAS7 (diallyl disulfide through diallyl heptasulfide) may be used as insecticides, acaricides, virucides, fungicides and plant growth regulators (3, 4); diallyl polysulfides may be used as stabilizers and polymerization inhibitors for unsaturated compounds and as antioxidant components (5); they may be used as pesticides for foliar application and other agricultural uses (6-8) and as tickicides (9); DAS2-DAS4 (diallyl disulfide through diallyl tetrasulfide) may be used for prevention of pine-wilt disease by controlling larvae of Bursaphelenchus xylophilus (10); they may be used as plant dormancy-inhibiting agents to accelerate budding (11); diallyl polysulfides may be used as optical materials having increased refractive index, as extreme-pressure additive and lubricating oil compound for automotive transmissions, and as protective electrolytes for lithium batteries (12); they may be used as amine-free corrosion inhibitors (13); in the form of cyclodextrin inclusion compounds they may be used as therapeutic agents (14); DAS3-DAS7 may be used as fungicides and lipid peroxidation inhibitors (15); diallyl polysulfides may be used as food preservatives and browning inhibitors (16).
There are also reports in the scientific literature on the use of diallyl trisulfide and tetrasulfide as antibiotics, antimicrobials, antithrombotic agents, antiparasitic agents, apoptosis-inducers and antitumor agents, anti-angiogenesis agents, and as compounds offering protection against toxicity caused by cadmium and other toxic metals. It can be seen that the range of applications is wide, and higher chain-length diallyl polysulfides would have utility in a number of technical fields.
Processes for the production of diallyl trisulfide, tetrasulfide and pentasulfide are known (17-24).